The self-cleaning ability of superhydrophobic metal surfaces has attracted extensive attention. The preparation of superhydrophobic material using the coating method is a common processing method. In this experiment, aluminum fins were processed by laser etching and perfluorinated two-step coating. The aluminum surface was modified using a femtosecond laser and 1H,1H,2H,2H- perfluorooctane triethoxysilane (PFOTES). A superhydrophobic aluminum surface with excellent mechanical stability and self-cleaning properties was obtained with the superhydrophobic contact angle (WCA) of 152.8° and the rolling angle (SA) of 0.6°. The results show that the superhydrophobic surface has an excellent cleaning effect compared with an ordinary surface in unit time. Then, a wear resistance test of the superhydrophobic surface was carried out by using the physical wear method. The results show that physical wear had a low influence on the hydrophobic property of the specimen surface. Finally, the Vickers hardness analysis found that the superhydrophobic surface hardness was significantly better than the ordinary surface hardness compared with the superhydrophobic surface hardness. Based on the excellent self-cleaning properties, wear resistance, and robustness of superhydrophobic materials, the laser-etched and perfluorinated superhydrophobic aluminum fins designed and manufactured in this study have broad application prospects in improving the heat transfer efficiency of finned heat exchangers.
This paper uses a new method combining nanosecond laser processing technology and sol-gel to design and manufacture mechanically robust micro-nano structure and modified SiO2@PDMS coating on copper substrate. The superhydrophobic composite surface was successfully synthesized with a water contact angle of 159.5° and a sliding angle of 0°. The characterization of the prepared superhydrophobic surface #3 was studied by optical profilometry, scanning electron microscopy, FT-IR spectroscopy, and X-ray photoelectron spectroscopy. In addition, self-cleaning, wear resistance, anti-icing, corrosion resistance, and NaCl deliquescence behavior were evaluated. The results show that surface #3 can efficiently remove contaminants within 200 s. In the anti-icing experiment, the delayed icing time and ice adhesion strength of surface #3 are 3.33 times and 3.86% of that of the ordinary copper surface, respectively, which can make the icicle slide easily. In the electrochemical test, the corrosion current density decreased by order of magnitude, and the corrosion inhibition efficiency reached 90.57%. Based on its excellent self-cleaning, mechanical robustness, anti-icing, and anti-corrosion properties, we believe that the composite modified surface of the laser-textured@SiO2@PDMS protective layer designed and manufactured in this study is expected to be used in engineering fields such as refrigeration, power grid, automobile and aerospace in the future.